ND113 GSA115 IVLAMC117 R119 ACSGM121 LIFVW200 VLIA201 LFMIV202 G203 ED205 G208 LVIM209 ILV223 PSDK224 SAT236 LMIF237 ND238 VLAI239 AST242 IVLA245 RK252 # found 21 key residues